Excavator assembly

ABSTRACT

An improved excavator assembly includes a main arm which is pivotally connected to an articulated vehicle, a lift arm pivotally connected to the main arm, and a bucket which is pivotally connected to an outer end portion of the lift arm. The main arm is pivoted forwardly by a first piston and cylinder assembly to crowd or force the bucket into a pile of dirt or other material while the vehicle remains stationary. A second piston and cylinder assembly is then operated to pivot the bucket to an upright load-carrying position. Once the bucket has engaged a load, a third piston and cylinder assembly is operated to pivot the lift arm upwardly to raise the bucket and the load. After the load has been raised, the second piston and cylinder assembly is operated to pivot the bucket to a downwardly facing down position to thereby dump the load.

United States Patent [72] Inventor Bronislaus I. Ulinski Palm Beach, Fla.

[2]] Appl. No. 840,912

[22] Filed July 11,1969

[45] Patented Mar. 30, 1971 [73] Assignee Eaton Yale & Towne Inc.

Cleveland, Ohio [54] EXCAVATOR ASSEMBLY Primary Examiner-Gerald M. Forlenza Assistant Examiner-John Mannix Att0rneyYont and Tarolli ABSTRACT: An improved excavator assembly includes a main arm which is pivotally connected to an articulated vehicle, a lift arm pivotally connected to the main arm, and a bucket which is pivotally connected to an outer end portion of the lift arm. The main arm is pivoted forwardly by a first piston and cylinder assembly to crowd or force the bucket into a pile of dirt or other material while the vehicle remains stationary A second piston and cylinder assembly is then operated to pivot the bucket to an upright load-carrying position. Once the bucket has engaged a load, a third piston and cylinder assembly is operated to pivot the lift arm upwardly to raise the bucket and the load. After the load has been raised, the second piston and cylinder assembly is operated to pivot the bucket to a downwardly facing down position to thereby dump the load.

Patented March 30, 1971 4 Sheets-Sheet 1 ,1 ua-W. A m ,l w x INVENTOI? Q 5201145444113 1'. UL/A/S/(l Patentefl Mmmh 3%, mm 3,5725% 4 Sheets-Sheet 2 mweuroe Mow/sums I. (/L INS/(l Patented March 30, 1971 3,572,531

4 Sheets-Sheet 3 WVE/VTOA" EKG/108L405 I (/L/A/S/f/ BY MJw/Z' 4 Sheets-Sheet 4 EXCAVA'IGR ASSEMBLY The present invention relates generally to a new and improved load-handling apparatus and more particularly to a front end loader assembly.

An object of this invention is to provide a new and improved load-handling apparatus which is capable of loading a large hauling or load-carrying vehicle in a relatively short time.

another object of this invention is to provide a new and improved load-handling apparatus including a bucket capable of engaging relatively large loads, a first piston and cylinder assembly for crowding or forcing the bucket into engagement with a load without relying upon driving effort of wheels of a vehicle associated with the load-handling apparatus, and a second piston and cylinder assembly for quickly raising the bucket and a relatively large lead to a height at which the bucket is dumped into a hauling vehicle.

Another object of this invention is to provide a new and improved load-handling apparatus including a bucket which is connected to a vehicle by a lift arm and main arm, a first fluid actuator means being provided for pivoting the main arm relative to the vehicle to crowd or force the bucket into engagement with a lead while the wheels of the vehicle remain substantially stationary, a second fluid actuator means for raising the lift arm and the bucket once the load has been engaged, and a third fluid actuator means for-pivoting the bucket to dump the raised load.

Another object of this invention is to provide a new and improved load-handling apparatus in accordance with the preceding paragraph and further including a first pump for supplying fluid under pressure to an accumulator and to the third fluid actuator means for operating the bucket to the dump position and a second pump for supplying fluid under pressure to the first and second fluid actuators, a control valve is provided for blocking fluid flow from. the first pump to the first and second fluid actuators until a predetermined fluid pressure is attained in the accumulator.

These and other objects and features of the present invention will become more apparent upon a consideration of the following description taken in connection with the accompanying drawings wherein:

FIG. I is a schematic illustration of an articulated vehicle having a front end loader constructed in accordance with the present invention, the front end loader includes a bucket which is shown in dashed lines in an inactive or transport position and in solid lines in a load-engaging position;

FIG. 2 is a schematic illustration of the front end loader after the bucket has been forced or crowded into engagement with a load;

FIG. 3 is a schematic illustration of the front end loader of FIG. I with the bucket in a raised position;

FIG. 4 is a schematic illustration of the front end loader of FIG. 11 with the bucket in a raised dump position;

FIG. 5 is a schematic illustration, taken generally along the line 5-5 of FIG. 4, illustrating the relationship between the bucket, cylinder assemblies for pivoting the bucket between a plurality of operating positions, and a lift arm and cylinders for raising the bucket;

FIG. ti is a plan view of a main arm which is pivoted relative to the vehicle to crowd or force the bucket into engagement with a load;

FIG. 7 is a plan view further illustrating the structure of the lift arm of FIG. 5;

FIG. 8 is a plan view illustrating the structure of a bucket arm which is pivotally connected to the lift arm of FIG. 7;

FIG. 9 is a plan view of a bucket link which pivotally interconnects the bucket and the bucket arm; and

FIG. 10 is a schematic illustration of hydraulic circuitry for operating the front end loader of FIG. i.

A front end loader 10 forming a specific preferred embodiment of the present invention is shown in FIG. I. mounted on the front section 112 of an articulated vehicle 114 having relatively movable front and rear sections 12 and 16. The articulated vehicle 114 is of a relatively large size, as can be seen by comparison between the height of the man W, the front end loader I0 and the position of an operators cab 20. The relatively large size of the front end loader I10 enables it to be used to fill extremely large hauling vehicles or rigs in a relatively short time. To this end, the bucket 22 of the front end loader I0 is capable of quickly engaging relatively large loads, i.e. approximately 75,000 lbs. the operator of the vehicle 14 can then raise the bucket 22 and the engaged load to a substantial height (approximately 29 feet) in a comparatively short time (about 17 seconds by operation of the front end loader it). Of course the foregoing figures setting forth specific operating characteristics of the front end loader will vary depending upon the construction of the front end loader. Therefore, the specific operating characteristic figures should be considered as merely illustrating the relatively large size of the front end loader It).

The front end loader ill) includes a main arm 26 which is pivotally connected at its lower end portion to the front section 12 of the articulated vehicle 114 for movement about an axis which is coincident with the axis of rotation of front wheels 28 and M) of the vehicle. A lift arm 34 connects the bucket 22 with the main arm 26. The bucket 22 is pivotal by operation of a bucket cylinder or actuator assembly db to move the bucket 22 between an upright inactive or transport position, illustrated in dashed lines in FIG. l, and a lowered load engaging position, illustrated in solid lines in FIG. I.

When the vehicle 14 has been moved to a position adjacent a load to be engaged by the bucket 22, a crowd cylinder or actuator assembly 44 is operated from the retracted condition of FIG. 1 to the extended condition of FIG. 2. Extending the actuator assembly 44 pivots the main arm 26 forwardly or outwardly to crowd or force the bucket 22 into engagement with a pile of dirt or other material. It should be noted that while the bucket 22 is being crowded or forced into this material, the brakes of the articulated vehicle Ml are firmly set to lock the front wheels 23 and 30 and rear wheels 48 (FIG. I) against movement relative to a support surface 5%. Thus, the bucket 22 is forced or crowded into a pile of material without any driving and slipping of the wheels of the vehicle 14. After the bucket 22 has engaged a load, the bucket cylinder or actuator assembly 40 is retracted to pivot the bucket 22 to the upright load-carrying position illustrated in dashed lines in FIG. 2.

The loaded bucket 22 is raised by operating a lift cylinder or actuator assembly 54 from the retracted condition of FIG. 2 to the extended condition of FIG. 3. Once the bucket 22 has been raised to the desired height, the bucket cylinder or actuator assembly 30 is extended to operate a bucket linkage 58 and thereby pivot the bucket 22 from the upright load carrying position of FIG. 3 to the downwardly facing dump position of FIG. 4. After the load has been dumped, the crowd cylinder assembly 44, lift cylinder assembly 5 3 and bucket cylinder assembly 4b are all retracted to operate the front end loader 10 back to the load engaging position illustrated in solid lines in FIG. 1.

The bucket 22 is crowded or forced into material to be moved by extending the crowd cylinder or actuator assembly 44 to pivot the main arm 26 forwardly or outwardly (see FIGS. 1 and 2). During this pivotal movement of the main arm 26, the bucket cylinder or actuator assembly 4t) maintains the bucket 22 with its forward end or lip 62 immediately adjacent to the ground or support surface 5%. To provide the enormous forces necessary to force the large bucket 22 into a pile of material, the crowd cylinder or actuator assembly 44 includes a pair of piston and cylinder assemblies as and of (see FIG. 5). The piston and cylinder assemblies as and his are located adjacent to left and right sides, respectively, of the front section 112 of the articulated vehicle 114. The inner end portions of the piston and cylinder assemblies 66 and 63 are pivotally connected at 72 and 74 to the front section 12 of the articulated vehicle 114 The outer end portions of the piston and cylinder assemblies as and lid are pivotally connected at 76 and 7b to the main arm 26 at locations intermediate the pivot connection 32 (FIGS. 1 and a) between the main arm and the vehicle 1d and a pivot connection 82 between the main arm as and the lift arm 3d.

Upon operation of the piston and cylinder assemblies 66 and 68 to their extended conditions, the main arm 26 is pivoted outwardly to crowd or force the bucket 22 into engagement with a pile of dirt or other material. This outward pivotal movement of the main arm 26 moves the pivot connection 82 from an innermost position (FIG. 1) wherein it is rearwardly of a vertical plane extending through the axis of rotation of the front wheels 28 and 30 of the articulated vehicle 14 to an outermost position (FIG. 2) wherein the pivot connection 82 is forwardly of the vertical plane extending through the axis of rotation of the front wheels of the vehicle. In addition, this outward movement of the main arm 26 moves the pivot connections 76 and 78 for the piston and cylinder assemblies 66 and 68 from a position inwardly of the vertical plane through the axis of rotation of the front wheels 28 and 30 of the vehicle to a position in which the pivot connections 76 and 78 intersect this vertical plane. When the bucket 22 is in the raised position of FIG. 3, the main arm 26 transmits load forces almost straight downwardly to the front section 12 of the articulated vehicle 14.

Once the bucket 22 has engaged a load, it is pivoted from the load-engaging position, shown in solid lines in FIG. 2, to the upright or load-carrying position, illustrated in dashed lines in FIG. 2, by operation of the bucket actuator assembly 44). The bucket actuator assembly 40 includes a pair of piston and cylinder assemblies 86 and 88 (FIG. having inner ends pivotally connected at 92 and 94 to a mounting arm assembly 96. The mounting arm assembly 96 is fixedly connected to the lift arm 34 and projects from the lift arm in a generally downward direction (FIGS. 2 and 3).

The piston and cylinder assemblies 86 and 88 extend through an opening 100 (see FIGS. 5 and 7) formed in the lift arm 34 between a pair of side stringers or sections 104 and 106 which are fixedly interconnected by a plate 108 in which the opening 100 is cut. The upper end portions of the piston and cylinder assemblies 86 and 88 are pivotally connected at 112 and 114 (FIG. 5) with the bucket linkage assembly 58. Thus, the bucket actuator assembly 40 is pivotally connected to the mounting arm assembly 96 on the lower side of the lift arm 34 and extends through the opening 100 in the lift arm and is pivotally connected with the bucket linkage 58 on the upper side of the lift arm.

The bucket 22 and the load therein are moved from the lowered position of FIG. 2 to the raised position of FIG. 3 by extending the lift cylinder or actuator assembly 54 from the almost completely retracted condition of FIG. 2 to the extended condition of FIG. 3. Extending the actuator assembly 54 pivots the lift arm 34 upwardly relative to the main arm 26 about the connection 82. During this upward movement of the crowd cylinder or actuator assembly 44 holds the main arm 26 in the upright position of FIGS. 2 and 3. The lift cylinder or actuator assembly 54 includes a pair of piston and cylinder assemblies I20 and 122 (FIG. 5) which are pivotally connected at 126 (FIGS. 2 and 3 to the front section 12 of the vehicle. The pivot connection 126 is located forwardly of a vertical plane through the axis of rotation of the front wheels 28 and 30 and below a horizontal plane through this axis of rotation (only the connection 126 for the piston and cylinder assembly 122 is illustrated in the drawings). The piston and cylinder assemblies 120 and 122 are pivotally connected to the lift arm 34 at pivot connections 128 and 130. The pivot connections 128 and 130 are located outwardly of the pivot connection 82 between the main arm 26 and lift arm 34.

As the bucket 22 and load are being raised, the bucket actuator assembly 40 is extended somewhat to maintain the bucket 22 in a predetermined upright orientation. The upward pivoting movement of the lift arm 34 pivots the mounting arm wsembly 96. The pivot connections 92 and 94 (FIG. 5) between the mounting arm assembly 96 and the piston and cylinder assemblies 86 and 88 move from a position inwardly or rearwardly of a vertical plane through the axis of rotation of the front wheels 28 and 30 to a position outwardly of forwardly of this plane. By extending the bucket actuator assembly 40 as the mounting arm assembly moves forwardly, the

bucket 22 is maintained in substantially the same orientation relative to a horizontal plane while the bucket is being raised.

Once the bucket 22 and the load therein have been raised to the desired level, the bucket actuator assembly 40 is further extended to operate the bucket linkage 58 and pivot the bucket 22 relative to the lift arm 34 from the upright load-carrying position of FIG. 3 to the dump position of FIG. 4. The bucket linkage assembly 58 includes a bucket arm 134 (FIG. 8) having a lower end portion pivotally connected at 136 (FIG. 4) to the lift arm 34 and an upper end portion which is pivotally connected at 112 to the piston and cylinder assemblies 86 and 88 of a bucket actuator assembly 40. The bucket arm 134 is connected to the bucket 22 by a bucket link 140 (FIG. 9) having an inner end portion connected to a bucket arm I34 and bucket actuator assembly 40 at the connection 112 (see FIGS. 4 and 5). The outer end of the bucket link 140 is pivotally connected at 142 to the bucket 22. It should be noted that the bucket 22 is connected to the outer end of the lift arm 34 by a pair of pivot connections 146 and 148 (see FIG. 5) to the side stringers 104 and 106 at locations sidewardly of the pivot connection 142 between the bucket 22 and the bucket link 140.

Upon operation of the bucket actuator assembly 40 to the extended position, the bucket arm 134 is swung forwardly or outwardly so that the pivot connection 112 moves outwardly to pivot the bucket link 140 downwardly to the position illustrated in FIG. 4. It should be noted that the bucket actuator assembly 40 is extended for a relatively large distance so that the pivot connection 112 between the bucket actuator assembly 40 and the bucket linkage 58 moves from a position rearwardly or inwardly of the pivot connection 148 between the bucket 22 and the lift arm 34 to a position outwardly and upwardly of the pivot connection 148. This enables the bucket 22 to be pivoted through a relatively large angle so that it faces downwardly to enable the bucket to be quickly emptied of its load.

After the bucket 22 has been dumped, the actuator assemblies 44, 54, and 40 are retracted to operate the front end loader 10 back to the load-engaging position the pivot connection 136 between the bucket arm 134 and lift arm 34 is intermediate the front wheels 28 and 30 of the articulated vehicle 14.

Hydraulic circuitry for operating the crowd cylinder or actuator assembly 44, the lift cylinder or actuator assembly 54, and the bucket cylinder or actuator assembly 40 is illustrated schematically in FIG. 10. In addition, the hydraulic circuitry 160 provides fluid pressure for operating a power steering assembly 162, vehicle brakes 164, and a piston and cylinder assembly 166 for raising the hood of the engine compartment for the articulated vehicle 14. The power steering assembly I62, brake assembly 164 and hood cylinder assembly 166 are associated with suitable control valves I70, 172 and 174 to effect operation of these assemblies in a known manner. Therefore, it is believed that a further description of these assemblies is not necessaryat this time. However, it should be noted that the brake assembly 164 is connected with the operators seat 175 by a linkage 176. When the operator leaves the seat 175, a spring 177 pivots the seat upwardly to cause the linkage 176 to operate the valve or master cylinder 172 to exhaust a wheel cylinder 178 so that springs 179 apply the brakes in a known manner.

The hydraulic circuitry 160 includes three pumps 180, 182 and 184 which are connected to a common fluid reservoir I86. Hydraulic fluid within the reservoir 186 is continuously cleaned by a power filter 188. This relatively clean hydraulic fluid flows under the influence of gravity through a final filter 190 to the pumps 180, 182, and 184.

An accumulator 194 is connected in fluid communication with the pump 180. The accumulator 194 holds a substantial volume of fluid at a relatively high pressure to insure that, during normal operating condition, there is always sufficient fluid pressure available to operate the power steering 162, the brakes 164, and the bucket cylinder or actuator assembly 40.

Thus, the accumulator 1194 is connected in fluid communication with the bucket cylinder or actuator assembly 40 by a fluid conduit 198 and is connected in fluid communication with the power steering assembly M2 and brakes E64 by a fluid conduit 202. A high-pressure relief valve 2% is provided for venting the conduits 1% and 202 to the reservoir 186 in response to the presence of a fluid pressure in the conduits which is in excess of a predetermined fluid pressure.

The pumps Hi2 and 184 provide fluid under pressure to operate the crowd cylinder or actuator assembly 44 and the lift cylinder or actuator assembly 54. The flow of fluid from the pumps 182 and 184 to these actuator assemblies through a fluid conduit are is controlled by an open-center six-way valve 2R2 of known construction The valve 212 is selectively actuatable by an operator in the cab 20 (see FIG. 1) of the articulated vehicle M to control the operation of the front end loader It A relief valve 216 is provided for exhausting the conduit 211i) to the reservoir W6 when the pressure in the conduit 210 exceeds a predetermined pressure. Fluid is returned to the reservoir W6 from the actuator assemblies 44, 54, and 4'0, the steering assembly 162, and the brake assembly 164 through conduits 220, 222 and 224.

Fluid flow from the pump I80 to the conduit 1110 is blocked by a two-way solenoid-operated valve 230 which is normally closed. The valve 230 insures that fluid from the pump Ml) flows to the accumulator 194 to pressurize the accumulator to a predetermined minimum pressure. Therefore, under normal operating conditions there is always sufficient fluid under pressure to operate the equipment associated with the accumulator I94. When the fluid pressure in the accumulator 194 and the conduit 198 reaches the predetermined minimum pressure, a pressure switch 232 is closed to complete a circuit through leads 234, 236 and 238 to actuate the solenoid valve 2% to an open condition. When the solenoid valve 230 is open, fluid from the pump 1180 can flow through a check valve 242 to the fluid conduit 210 and the actuator assemblies 44 and 54. However, fluid flow from the accumulator 194 through the open valve 230 is blocked by a check valve 246.

Operation of the bucket cylinder or actuator assembly 40 is controlled by a four-way solenoid valve 250 which can be operated by either solenoids 252 and 254 or manually by means of a suitable control member (not shown). To keep a load from spilling out of the bucket 22, it is necessary to keep the bucket in an upright position relative to a horizontal plane as the bucket is being lifted from the lowered position shown in dashed lines in FIG. 2 to the raised position shown in FIG. 3. in addition it is also important to maintain the bucket in an upright orientation relative to a horizontal plane while the d vehicle 24 is being driven along rough or hilly ground which may cause the orientation of the vehicle itself to vary relative to the horizontal plane.

To enable the bucket 22 to be maintained in an upright position relative to the horizontal plane under these operating condition, a detector switch of the gravity type, illustrated schematically at 264) in FIG. 10, is mounted on the bucket for controlling the operation of the bucket actuator assembly 40. The switch 260 is operated to a closed condition in response to a tilting of the bucket from the predetermined upright loadcarrying position. Closing the switch 2M) completes the circuit through leads 262 to energize an appropriate one of the solenoids 252 or 254 to operate the valve 250 and the bucket actuator assembly 40 to return the bucket 22 back to the upright position. The operator of the vehicle can actuate a suitable manual control to override the solenoids 252 and 24 and operate the valve 25% to thereby effect a pivotal movement of the bucket 22 to any desired operating position.

After the front end loader 110 has been utilized for a relatively long period of time, it is contemplated that seals and various other parts of the actuator assemblies 44 44 and 54 will become worn and require replacing. To facilitate this replacement, the actuator assemblies 40, 44 and 54 have cylinders with the same diameter bore and interchangeable internal and external parts. To further facilitate the repair of worn or broken components of the front end loader 110, a boom 270 (FIG. 1) is pivotally connected at 272 to the vehicle 14. The boom 270 is pivotal from the rearwardly extending position shown in solid lines in FIG. 1 to the forwardly extending position shown in dashed lines in FIG. 1. A trolley 274 is movable along the boom 270 and is operable to engage a desired component of the front end loader l0 to facilitate repairing or replacing this component.

In view of the foregoing description, it can be seen that a front end loader lltl constructed in accordance with the present invention is capable of lifting extremely large loads and dumping them into relatively high hauling vehicles. To enable the bucket 22 to penetrate into material to be engaged by the bucket, the crowd cylinder or actuator assembly 44 is operable to pivot the rrlain arm 26 forwardly with a relatively large force. It should be noted that the wheels of the articulated vehicle are locked while the bucket 22 is being forced or crowded into a pile of dirt or other material so that the tractive force of slipping or spinning tires of the vehicle is not relied upon to crow the bucket 22 into the material. The front end loader i0 is capable of lilting a load quickly to a relatively large height by operation of the lift cylinder or actuator assembly 54 which pivots the lift arm 34 relative to the main arm 26. Once the load and bucket 22 have been raised to the desired level, the bucket actuator assembly 40 is extended to operate the bucket linkage 58 and dump the bucket 22.

Iclaim:

l. A load-handling apparatus for moving loads relative to a vehicle, said apparatus compn'sing a main arm pivotally connected at a lower end portion to said vehicle, a lift arm pivotally connected at an inner end portion to an upper end portion of said main arm, bucket means pivotally connected to an outer portion of said lift arm and movable between a first operating position in which said bucket means is adapted to engage a load and a second operating position in which said bucket means is adapted to transport a load, first power actuator means pivotally connected to said vehicle and said main arm for moving said main arm relative to said vehicle to facilitate engagement of a load by said bucket means when said bucket means is in said first operating position, second power actuator means pivotally connected to said vehicle and said lift arm for raising said lift arm and said bucket means with a load therein when said bucket means is in said second operating position, and third power actuator means having an inner end portion connected with the inner end portion of said lift arm inwardly of the pivot connection between said second power actuator means and said lift arm and an outer end portion connected with said bucket means for moving said bucket means between said first and second operating positions.

2. A load-handling apparatus as set forth in claim I further including a mounting arm fixedly connected to the inner end portion of said lift arm, said third power actuator means being pivotally connected to said mounting arm at its inner end portion.

3. A load-handling apparatus as set forth in claim 2 further including bucket linkage means for operatively connecting the outer end portion of said third power actuator means with said bucket means, said bucket linkage means including a bucket arm pivotally connected at an upper end portion to the outer end portion of saidthirdpower actuator means and at a lower end portion to said lift arm outwardly of the pivot connection between said lift arm and said second power actuator means, and a bucket link pivotally connected at an outer end portion to said bucket means and pivotally connected at an inner end portion to said outer end portion of said third power actuator means and the upper end portion of said bucket arm.

4. A load-handling apparatus as set forth in claim 3 wherein said third power actuator means is operable to actuate said bucket linkage means to pivot said bucket means to a third operating position in which said bucket means faces generally downwardly to facilitate emptying said bucket means, said bucket linkage means being operable to a position in which the pivot connection between said third power actuator means and said bucket linkage means is outwardly of the pivot connection between said bucket means and said lift arm to pivot said bucket means to said third operating position.

5. A load-handling apparatus as set forth in claim 1 wherein said lift arm includes first and second fixedly interconnected side stringers which extend outwardly to said bucket means with an opening in said lift arm between said side stringers, said third power actuator means extending outwardly through the opening in said lift arm from the connection with the inner end portion of said lift arm to the connection with said bucket means.

6. A load-handling apparatus as set forth in claim 5 wherein said third power actuator means is moved from a position in which the connection between the inner end portion of said third power actuator means and said lift arm is inwardly of the connection between said main arm and said lift arm to a position in which the connection between the inner end portion of said third power actuator means and said lift arm is outwardly of the connection between said main arm and said lift arm.

7. A load-handling apparatus as set forth in claim 5 wherein said third power actuator means is operable to an extended condition in which it extends outwardly past the pivot connection between said lift arm and said bucket means to thereby pivot said bucket means to a third operating condition in which said bucket means faces generally downwardly to facilitate emptying said bucket means.

8. A load-handling apparatus as set forth in claim 1 wherein said main arm is pivotally connected to said vehicle along an axis which is coincident with the axis of rotation of the front wheels of said vehicle.

9. A load-handling apparatus as set forth in claim 8 wherein said second power actuator means is connected to said vehicle at a location intermediate the front wheels of said vehicle and below their axis of rotation.

10, A load-handling apparatus as set forth in claim 9 wherein said main ann is movable relative to said vehicle under the influence of said first power actuator means from a position in which the pivot connection between said main arm and said lift arm is inwardly of a vertical plane through the axis of rotation of the front wheels of said vehicle to a position in which the pivot connection between said main am and said lift arm is outwardly of the vertical plane.

11. A load-handling apparatus as set forth in claim 9 wherein said lift arm is movable to an innermost lowered position in which at least a portion of said bucket means is between the front wheels of said vehicle when said bucket means is in said second operating condition.

12. A load-handling apparatus as set forth in claim 1 further including control means operatively connected to said third power actuator means for automatically controlling the operation of said third power actuator means to maintain said bucket means in a predetermined upright orientation relative to a horizontal when said bucket means is in said second operating condition even though the orientation of said vehicle relative to the horizontal plane varies while said bucket means is in said second operating condition.

13. A load-handling apparatus as set forth in claim 1 further including a plurality of pumps for supplying fluid under' pressure and hydraulic circuit means for connecting said pumps in fluid communication with said power actuator means, said hydraulic circuit means including accumulator means for holding fluid under pressure, first fluid conduit means for connecting said accumulator means in fluid communication with one of said pumps and for connecting said accumulator means in fluid communication with said third power actuator means to thereby enable fluid under pressure to flow to said third power actuator means to effect operation of said third power actuator means to move said bucket means between said operating positions, second fluid conduit means for connecting another of said pumps in fluid communication with said first and second power actuator means to enable fluid under pressure to flow from said other pump to said first and second power actuator means, and valve means responsive to the fluid pressure in said accumulator means for connecting said first fluid conduit means in fluid communication with said second fluid conduit means in response to the presence in said accumulator means of a fluid pressure which is at least as great as a predetermined fluid pressure.

14. A load-handling apparatus for moving loads relative to a vehicle, said apparatus comprising a main arm pivotally connected at a lower end portion to said vehicle, a lift arm pivotally connected at an inner end portion to an upper end portion of said main arm, bucket means pivotally connected to an outer end portion of said lift arm and movable between a first operating position in which said bucket means is adapted to engage a load and a second operating position in which said bucket means is adapted to transport a load, first fluid actuator means for moving said main arm relative to said vehicle to facilitate engagement of a load by said bucket means when said bucket means is in said first operating position, second fluid actuator means for raising said lift arm and said bucket means with a load therein when said bucket means is in said second operating position, third fluid actuator means for moving said bucket means between said first and second operating positions, a plurality of pumps for supplying fluid under pressure, first fluid conduit means for connecting one of said pumps in fluid communication with said first and second fluid actuator means, first valve means for controlling the flow of fluid under pressure through said first fluid conduit means to thereby control the operation of said first and second fluid actuator means, accumulator means for holding fluid under pressure, second fluid conduit means for connecting said accumulator means in fluid communication with another of said pumps and in fluid communication with said third fluid actuator means, second valve means for controlling the flow of fluid under pressure through said second fluid conduit means to said third actuator means to thereby control the operation of said third fluid actuator means, third valve means for controlling the flow of fluid under pressure frm said second fluid conduit means to said first fluid conduit means, pressure responsive means for operating said third valve means from a closed condition blocking fluid flow between said first and second fluid conduit means to an open condition enabling fluid under pressure from said other pump to flow from said second fluid conduit means to said first fluid conduit means in response to the presence of a fluid pressure in said accumulator means which is at least as great as a predetermined fluid pressure so that said first and second fluid actuator means are operated under the effect of only fluid from said one pump until the fluid pressure in said accumulator means is at least as great as the predetennined fluid pressure.

15. A load-handling apparatus as set forth in claim 14 further including check valve means operatively connected with said second fluid conduit means for blocking fluid flow from said accumulator means to said first fluid conduit means so that fluid under pressure from said accumulator means is utilized only to effect operation of said third fluid actuator means.

16. A load-handling apparatus as set forth in claim 14 further including means for detecting changes in the orientation of said bucket means from a predetermined orientation relative to a horizontal plane when said bucket means is in said second operating condition and for controlling operation of said second valve means in response to a change in the orientation of said bucket means from the predetermined orientation to effect operation of said third fluid actuator means to return said bucket means to the predetermined orientation whereby said bucket means is substantially maintained in the predetermined orientation relative to the horizontal plane during changes in the orientation to the horizontal plane during changes in the orientation of the vehicle relative to the horizontal plane.

17. A load-handling apparatus for moving loads relative to a vehicle, said apparatus comprising a main arm pivotally connected at a lower end portion to said vehicle at a location intermediate front wheels of said vehicle, a lift arm pivotally arm and movable between a first operating position in which said bucket means is adapted to engage a load, a second operating position in which said bucket means is adapted to transport a load, and a third operating position in which said bucket means faces generally downwardly to facilitate dumping a load, bucket linkage means operatively connected to said bucket means for moving said bucket means between said operating positions, first power actuator means pivotally connected at an inner end portion to said vehicle and pivotally connected at an outer end portion to said main arm at a location intermediate the upper and lower end portions of said main arm, said first power actuator means being operable to pivot said main arm relative to said vehicle to facilitate engagement of a load by said bucket means when said bucket means is in said first operating position, second power actuator means pivotally connected to said vehicle and said lift arm for raising said lift arm and said bucket means with a load therein when said bucket means is in said second operating position, a mounting arm fixedly connected to the inner end portion of said lift arm, and third power actuator means extending through the opening in said lift arm having an inner end portion pivotally connected to said mounting arm on the lower side of said lift arm inwardly of the pivot connection between said second power actuator means and said lift arm and an outer end portion pivotally connected with said bucket linkage means on the upper side of said lift arm, said third power actuator means being operable to actuate said bucket linkage means to move said bucket means between said operating positions.

18. A load-handling apparatus as set forth in claim 17 wherein said main am is pivotally connected to said vehicle along an axis which is coincident with the axis of rotation of the front wheels of said vehicle and said second power actuator means is connected to said vehicle at a location'intermediate the front wheels of said vehicle and below their axis of rotation.

19. A load-handling apparatus as set forth in claim 17 wherein said bucket linkage means includes a bucket arm pivotally connected at an upper end portion to the outer end portion of said third power actuator means and at a lower end portion to said lift arm between said stringers and outwardly of the pivot connection between said lift arm and said second power actuator means, and a bucket link pivotally connected at an outer end portion to said bucket means and pivotally connected at an inner end portion to said outer end portion of said third power actuator means and the upper end portion of said bucket arm.

20. A load-handling apparatus as set forth in claim 17 further including control means for controlling the operation of said third power actuator means to substantially maintain said bucket means in a predetermined orientation relative to a horizontal plane when said bucket means is in said second operating position even though the orientation of said vehicle relative to the horizontal plane changes, said control means including detector means for detecting changes in the orientation of said bucket means from the predetermined orientation when said bucket means is in the second position and means for activating said third power actuator means in response to said detector means detecting a change in the orientation of said bucket means form the predetermined orientation to move said bucket means back to the predetermined orientatron.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 572 531 Dated March 30 1971 I v Bronislaus I Ulinski It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3 line 50 after "the", second occurrence ins lift arm 34 the Column 4 line 40 after "position" insert of Fig. l It should be noted that in this load engaging position Column 6 line 34 after "outer" inser end Column 8 line 35, before "actuator" insert fluid lines 69 and 70 cancel "to the horizontal plane during changes in the orientation"-.

Signed and sealed this 14th day of September 1971 (SEAL) Attest:

EDWARD M. FLETCHER ,JR. ROBERT GO'ITSCHALK V Attesting Officer Acting Commissioner of Pain 

1. A load-handling apparatus for moving loads relative to a vehicle, said apparatus comprising a main arm pivotally connected at a lower end portion to said vehicle, a lift arm pivotally connected at an inner end portion to an upper end portion of said main arm, bucket means pivotally connected to an outer portion of said lift arm and movable between a first operating position in which said bucket means is adapted to engage a load and a second operating position in which said bucket means is adapted to transport a load, first power actuator means pivotally connected to said vehicle and said main arm for moving said main arm relative to said vehicle to facilitate engagement of a load by said bucket means when said bucket means is in said first operating position, second power actuator means pivotally connected to said vehicle and said lift arm for raising said lift arm and said bucket means with a load therein when said bucket means is in said second operating position, and third power actuator means having an inner end portion connected with the inner end portion of said lift arm inwardly of the pivot connection between said second power actuator means and said lift arm and an outer end portion connected with said bucket means for moving said bucket means between said first and second operating positions.
 2. A load-handling apparatus as set forth in claim 1 further including a mounting arm fixedly connected to the inner end portion of said lift arm, said third power actuator means being pivotally connected to said mounting arm at its inner end portion.
 3. A load-handling apparatus as set forth in claim 2 further including bucket linkage means for operatively connecting the outer end portion of said third power actuator means with said bucket means, said bucket linkage means including a bucket arm pivotally connected at an upper end portion to the outer end portion of said third power actuator means and at a lower end portion to said lift arm outwardly of the pivot connection between said lift arm and said second power actuator means, and a bucket link pivotally connected at an outer end portion to said bucket means and pivotally connected at an inner end portion to said outer end portion of said third power actuator means and the upper end portion of said bucket arm.
 4. A load-handling apparatus as set forth in claim 3 wherein said third power actuator means is operable to actuate said bucket linkage means to pivot said bucket means to a third operating position in which said bucket means faces generally downwardly to facilitate emptying said bucket means, said bucket linkage means being operable to a position in which the pivot connection between said third power actuator means and said bucket linkage means is outwardly of the pivot connection between said bucket means and said lift arm to pivot said bucket means to said third operating position.
 5. A load-handling apparatus as set forth in claim 1 wherein said lift arm includes first and second fixedly interconnected side stringers which extend outwardly to said bucket means with an opening in said lift arm between said side stringers, said third power actuator means extending outwardly through the opening in said lift arm from the connection with the inner end portion of said lift arm to the connection with said bucket means.
 6. A load-handling apparatus as set forth in claim 5 wherein said third power actuator means is moved from a position in which the connection between the inner end portion of said third power actuator means and said lift arm is inwardly of the connection between said main arm and said lift arm to a position in which the connection between the inner end portion of said third power actuator means and said lift arm is outwardly of the connection between said main arm and said lift arm.
 7. A load-handling apparatus as set forth in claim 5 wherein said third power actuator means is operable to an extended condition in which it extends outwardly past the pivot connection between said lift arm and said bucket means to thereby pivot said bucket means to a third operating condition in which said bucket means faces generally downwardly to facilitate emptying said bucket means.
 8. A load-handling apparatus as set forth in claim 1 wherein said main arm is pivotally connected to said vehicle along an axis which is coincident with the axis of rotation of the front wheels of said vehicle.
 9. A load-handling apparatus as set forth in claim 8 wherein said second power actuator means is connected to said vehicle at a location intermediate the front wheels of said vehicle and below their axis of rotation.
 10. A load-handling apparatus as set forth in claim 9 wherein said main arm is movable relative to said vehicle under the influence of said first power actuator means from a position in which the pivot connection between said main arm and said lift arm is inwardly of a vertical plane through the axis of rotation of the front wheels of said vehicle to a position in which the pivot connection between said main arm and said lift arm is outwardly of the vertical plane.
 11. A load-handling apparatus as set forth in claim 9 wherein said lift arm is movable to an innermost lowered position in which at least a portion of said bucket means is between the front wheels of said vehicle when said bucket means is in said second operating condition.
 12. A load-handling apparatus as set forth in claim 1 further including control means operatively connected to said third power actuator means for automatically controlling the operation of said third power actuator means to maintain said bucket means in a predetermined upright orientation relative to a horizontal when said bucket means is in said second operating condition even though the orientation of said vehicle relative to the horizontal plane varies while said bucket means is in said second operating condition.
 13. A load-handling apparatus as set forth in claim 1 further including a plurality of pumps for supplying fluid under pressure and hydraulic circuit means for connecting said pumps in fluid communication with said power actuator means, said hydraulic circuit means including accumulator means for holding fluid under pressure, first fluid conduit means for connecting said accumulator means in fluid communication with one of said pumps and for connecting said accumulator means in fluid communication with said third power actuator means to thereby enable fluid under pressure to flow to said third power actuator means to effect operation of said third power actuator means to move said bucket means between said operating positions, second fluid conduit means for connecting another of said pumps in fluid communication with said first and second power actuator means to enable fluid under pressure to flow from said other pump to said first and second power actuator means, and valve means responsive to the fluid pressure in said accumulator means for connecting said first fluid conduit means in fluid communication with said second fluid conduit means in response to the presence in said accumulator means of a fluid pressure which is at least as great as a predetermined fluid pressure.
 14. A load-handling apparatus for moving loads relative to a vehicle, said apparatus comprising a main arm pivotally connected at a lower end portion to said vehicle, a lift arm pivotally connected at an inner end portion to an upper end portion of said main arm, bucket means pivotally connected to an outer end portion of said lift arm and movable between a first operating position in which said bucket means is adapted to engage a load and a second operating position iN which said bucket means is adapted to transport a load, first fluid actuator means for moving said main arm relative to said vehicle to facilitate engagement of a load by said bucket means when said bucket means is in said first operating position, second fluid actuator means for raising said lift arm and said bucket means with a load therein when said bucket means is in said second operating position, third fluid actuator means for moving said bucket means between said first and second operating positions, a plurality of pumps for supplying fluid under pressure, first fluid conduit means for connecting one of said pumps in fluid communication with said first and second fluid actuator means, first valve means for controlling the flow of fluid under pressure through said first fluid conduit means to thereby control the operation of said first and second fluid actuator means, accumulator means for holding fluid under pressure, second fluid conduit means for connecting said accumulator means in fluid communication with another of said pumps and in fluid communication with said third fluid actuator means, second valve means for controlling the flow of fluid under pressure through said second fluid conduit means to said third actuator means to thereby control the operation of said third fluid actuator means, third valve means for controlling the flow of fluid under pressure from said second fluid conduit means to said first fluid conduit means, pressure responsive means for operating said third valve means from a closed condition blocking fluid flow between said first and second fluid conduit means to an open condition enabling fluid under pressure from said other pump to flow from said second fluid conduit means to said first fluid conduit means in response to the presence of a fluid pressure in said accumulator means which is at least as great as a predetermined fluid pressure so that said first and second fluid actuator means are operated under the effect of only fluid from said one pump until the fluid pressure in said accumulator means is at least as great as the predetermined fluid pressure.
 15. A load-handling apparatus as set forth in claim 14 further including check valve means operatively connected with said second fluid conduit means for blocking fluid flow from said accumulator means to said first fluid conduit means so that fluid under pressure from said accumulator means is utilized only to effect operation of said third fluid actuator means.
 16. A load-handling apparatus as set forth in claim 14 further including means for detecting changes in the orientation of said bucket means from a predetermined orientation relative to a horizontal plane when said bucket means is in said second operating condition and for controlling operation of said second valve means in response to a change in the orientation of said bucket means from the predetermined orientation to effect operation of said third fluid actuator means to return said bucket means to the predetermined orientation whereby said bucket means is substantially maintained in the predetermined orientation relative to the horizontal plane during changes in the orientation to the horizontal plane during changes in the orientation of the vehicle relative to the horizontal plane.
 17. A load-handling apparatus for moving loads relative to a vehicle, said apparatus comprising a main arm pivotally connected at a lower end portion to said vehicle at a location intermediate front wheels of said vehicle, a lift arm pivotally connected at an inner end portion to an upper end portion of said main arm, said lift arm including a plurality of fixedly interconnected stringers with an opening therebetween, bucket means pivotally connected to an outer end portion of said lift arm and movable between a first operating position in which said bucket means is adapted to engage a load, a second operating position in which said bucket means is adapted to transport a load, and a third operating position in which said bucket means faces generally downwardly to facilitate dumping a load, bucket linkage means operatively connected to said bucket means for moving said bucket means between said operating positions, first power actuator means pivotally connected at an inner end portion to said vehicle and pivotally connected at an outer end portion to said main arm at a location intermediate the upper and lower end portions of said main arm, said first power actuator means being operable to pivot said main arm relative to said vehicle to facilitate engagement of a load by said bucket means when said bucket means is in said first operating position, second power actuator means pivotally connected to said vehicle and said lift arm for raising said lift arm and said bucket means with a load therein when said bucket means is in said second operating position, a mounting arm fixedly connected to the inner end portion of said lift arm, and third power actuator means extending through the opening in said lift arm having an inner end portion pivotally connected to said mounting arm on the lower side of said lift arm inwardly of the pivot connection between said second power actuator means and said lift arm and an outer end portion pivotally connected with said bucket linkage means on the upper side of said lift arm, said third power actuator means being operable to actuate said bucket linkage means to move said bucket means between said operating positions.
 18. A load-handling apparatus as set forth in claim 17 wherein said main arm is pivotally connected to said vehicle along an axis which is coincident with the axis of rotation of the front wheels of said vehicle and said second power actuator means is connected to said vehicle at a location intermediate the front wheels of said vehicle and below their axis of rotation.
 19. A load-handling apparatus as set forth in claim 17 wherein said bucket linkage means includes a bucket arm pivotally connected at an upper end portion to the outer end portion of said third power actuator means and at a lower end portion to said lift arm between said stringers and outwardly of the pivot connection between said lift arm and said second power actuator means, and a bucket link pivotally connected at an outer end portion to said bucket means and pivotally connected at an inner end portion to said outer end portion of said third power actuator means and the upper end portion of said bucket arm.
 20. A load-handling apparatus as set forth in claim 17 further including control means for controlling the operation of said third power actuator means to substantially maintain said bucket means in a predetermined orientation relative to a horizontal plane when said bucket means is in said second operating position even though the orientation of said vehicle relative to the horizontal plane changes, said control means including detector means for detecting changes in the orientation of said bucket means from the predetermined orientation when said bucket means is in the second position and means for activating said third power actuator means in response to said detector means detecting a change in the orientation of said bucket means form the predetermined orientation to move said bucket means back to the predetermined orientation. 